Definition of Relation. A relation is a set of ordered pairs. This seems like an odd definition but weâll need it for the definition of a function (which is the main topic of this section).
Classic (Swedish) massage and Thai massage have been proven to relieve chronic lower back pain. Classic massage for lower back pain is a technique that relaxes muscles in the area through the application of pressure. The area is rubbed in the direction in which blood flows back to the heart. Thai massage, on the other hand, is a technique that pulls and stretches the area of the back and neck.
This back massager is multifunctional (neck, upper back, lower back or abdomen), with four bidirectional pressure nodes. It offers heated massage, and the arm loops allow you to intensify the pressure by pressing down or lightening up. (Amazon, $40) Highlight review: I use this every morning due to lower back pain.